Other than Egg Bound, what would cause a chicken to walk like a penguin?

[Zeoliter]

I have a Red Star hen that has been walking like a penguin for more than 2 weeks. Abdomen feels distended. She's eating and drinking and poop is a mixture of runny and soft. If she was egg bound she'd be dead already. What could be the cause? I haven't felt inside the vent yet as it would be weird to be egg bound for so long. I have isolated her to a cage in the house and have given her a couple of warm boaths for good measure. Any ideas on what I need to do? Thanks!

 

[DobieLover]

Organ failure causing ascites.
Tumors causing internal pressure.
EYP.